Transmission-dynamometer.



F. D. EVERETT. TRANSMISSION DYNAMOMETER. APPLICATION min 0:013, 1915.

Patented Jan. 16-, 1917.

VOLT'METER MAGNETO GENERATOR- F. 0. E VERET T. TRANSMISSION DYNAMOMETER.

'APPLICATION FILED DEC. 13, 1915.

1,212,751 I I PatentedJah.16,1917.

4 SHEETS-SHEET 2- F. D. EVERETT.

TRANSMISSION DYNAMOMETER.

APPLICATION FILED DEC.13, 1915.

Patented Jan. 16,1917" 4 $HEET$-$HEET 3 IIIIIIIIIIIII VIIIIIIIIIIIIIIIIII'II F. n. EVERETT.

TRANSMISSION DYNA'M'OMETER. APPLLCATION FIL ED DEC. 13; 1915- 1 ,2]. 2,75 1 w Patented Jan. 16, 1917.

. 4 SHEETS-SHEET 4- mission-Dynamometers, of which the fol- 'Referring to the drawings, Figure 1 is a FRANCIS DEWEY EVERETT, 0F SARANAC LAKE, NEW YORK.

rnansmssron-nynnmomnrnn.

To all whom it may concern:

Be it known that I, FRANCIS DEWEY Ev- ERETT, a citizen of the United States, reading at SaranacLake, in the county of Essex and State of New York, have invented certain new and useful Improvements in Translowing is a. specification.

My invention relates to a transmission dynamometer, which is an apparatus for measuring the power transmitted in a shaft, without absorblng any of the power.

The object of my inventionvis to provide a transmission dynamometer, or apparatus of the type referred to, of simple construction, and effective in operation, to obtain the power transmitted in a shaft, or other described.

i equivalent rotary device, and to register the actual power, and not the torque only in the shaft.

My invention consists in certain novel features of construction of my transmission will be hereinafter fully I pulley 1s shown complete in this figure and,

dynamometer as My improvements, as herein described and shown in the drawings, consist of such a system of electrical connections that the apparatus will take account automatically of all variationsof' speed of rotation of the shaft, thereby making it applicable to variable speed machines.

The apparatus consists of a direct current magneto generator giving a voltage proportional to the speed, driven by the shaft in which the power is to be measured, and means,not new in the'art, of producing relative motion between two devices proportional to'the torque in said shaft. A fixed resistance coil is located on one side of said devices, and with both terminals connected by insulating. conductors, slip rings, and brushes to the terminals of the magneto, thereby forming a closed circuit of constant resistance; a sliding contact bearing on the resistance coil, whose position relative to one end of said coil .is dependent upon the relative motion of the two devices first mentioned, and a voltmeter with terminals connected by insulating conductors, slip rings, and brushes to the sliding contact, and to one terminal of said resistance coil, thereby giving readings proportional to the voltage drop in said coil etween the sliding contact and the end terminal of the coil; by proper'calibration Specification of Letters Patent. Application filed December 13, 1915. Serial No. 36,431.

' rim.

Patented Jan. 1c, 1917.

apparatus embodying my improvements, to

enable those skilled in the art to understand the construction and operation thereof.

general view of a transmission dynamometer embodying my improvements, and parts connected therewith. Fig. 2 is a side view of the transmission dynamometer shown in Fig. 1, looking in the direction of arrow m,

Fig. 3,-vwith the pulley rim broken away, to lllustrate the parts concealed in Fig. 1. Fig. 3 is an end view of the parts shown in Fig. 2, looking in the direction of arrow 1), same figure, and showing. the complete pulley of arrow a, same figure. Fig. 5 1s an end Fig. 4. is a central vertical section, Y on line 4, 4, Flg. 3, looking in the direction view of the parts shown in Fig. 2, looking in the direction of arrow 0, same figure; the

ig. 6 is a'diagrammatic view of the electrical connections paratus.

In the accompanying drawings, 1 is a rotary shaft in which the power is to be and other parts of my apmeasured, 2 is a hub secured to the shaft 1,

in this instance by a key 3, see Fig. 4. The

'hub 2 has in this instance three (outwardly springs 12, 13, and 14;, which are secured respectively at one, end to a spoke 8, 9, or 10, by a stud 15, and at their other end to an arm 4, 5, or 6 on the hub 2, by a stud'lfi, see Fig.5.

The hub 7 of the pulley 7 is free to rotate about the inner hub 2, except forthe springs 12, 13, and-14, and when the pulley 7 is driven, in this instance by the belt 11, the

drive is transmitted through the springs 12,

13, and 14, to 'the inner hub 2, and to the shaft 1.,

insulating disk 17, of fiber or other sultable material, is secured to the arms 4,

.see Fig. 5.

5, and 6, in this instance b. means of screws 18, see Fig. 4. The dis -17 has secured thereto aseries of brass slip rin s M, MV, and V.- A shaft 19, see Fig. 4, as in this instance an annular disk 19 on its inner -end, which is secured to the end of the hub 2, in this instance by screws 20, and forms an extension of the shaft 1.

A fiber brush holder 21 is mounted on a collar 22,,which is loosel mounted on the shaft 19,see Fig. 4. .To t e brush holder 21 are secured, in this instance by screws 23,. a series of brass brushes V, M+V and M', which engage the brass slip rlngs V, MV, and M, respectively.

24 is a segment ofinsulating mater al, secured to the arms 5 and 6 onthe hub 2 The segment 24 thereon a fixed resistance wi're coil 25, which is engaged by a brass contact brush 26, see

Fig. 3, which is secured to the rim of the pulley 7, and slides along the surface of the resistance coil 25, as the springs 12, 13, and

- V+ and the sliding contact trical contact with the coil.

14 extend. The adjacent turns of the coil 25 are insulated from one another by suitable insulation, but are bare on the outer edge, so that the brush 26 makes a good elec- The extension oi? the springs 12, 13, and 14'is proportional 'to the torque transmitted, and hence the fircentage of the total voltage applied to and M-, measured between M or V, is also proportional to the torque.

The ends of the resistance coil 25 are electrically connected by means ofwires 28 and 29, see Fig. 2, toslip rings M, and MV. The

contact brush 26is electrically connected by meansof wire 27, see Fig. 2, to the slip ringV. On the shaft 19 is secured, in this instance, a grooved pulley 30, which is con.-

nected by a belt 31 with a grooved pulley 32 on the shaft 33 of the magneto 34, see- Fig. 1, to drive the magneto from the shaft 1 A, Wire connection 35 extends between the minus terminal of the magneto 34:, and the contact brush M--, whichbears against the slip ring M, see Fig. 1. A wire connection '36 extends between the plus terminal of the magneto, and the contact brush M+V+, which bears against the slip ring MV, see

he voltmeter 37 has an electrical connection 38 between its minus terminal and the contact brush V, which engages the slip ring V, and also has an electrical connection 39 between the plus terminal thereof,

and the contact brush M+V+, which enga the slip ring MV.

he apparatus is calibrated so that the voltmeter 37 will read directly the horsepower transmitted. Referring to Fig. 6, it willbe seen that the current generated by the rotation of i has wound mentioned.

maeto generator 34, will take the follow ing course: from one terminal of the magneto generator 34,through the wire 35 to the brush M, slip ring M, through the wire 28, through the resistance coil 25 through the wire 29, slip ring .MV, brush M-l-V+, and wire36, back to the magneto generator 34. Thus the voltage generated at the terminals of the magnetogenerator 34 is consumed-by,

the current flowing through the resistance coil 25. The voltmeter 37 is connected by wire 38, brush V, slip ring V, and Wire 27, to the sliding contact 26, which bears on the resistance coil 25, and also by wire 39, brush M+V+, slip ring MV, and wire '29, to the right hand terminal of the coil 25. Therefore the voltmeter 37 will give readmgs proportional to the voltage drop in the reslstance coil 25, between the terminal connected to the wire 29, and the point where shaft, and said two devices, and a voltmeter u forthe reading of the horsepower trans mitted, and a resistance coil, and electrical circuits connecting said resistance coil and said magneto generator in series, and connecting said vo tmeter, to measure the voltage drop in a variable ortion of said resistance coil, by means 0 a moving contact,

whose movement, relative to the resistance coil, is controlled by the two devices above 2. A transmissiondynamometer, comprismg a direct current magneto generator, a

shaft in which the power is to be measured means for driving said generator from said shaft, means for 'roducing relative motion between two devices connected with said shaft, proportional to the torque in said shaft, and said two devices, and a fixed resistance coil, and a contact, forming an electrical connection, whose-position on the resistance coil is controlled by the mechanical connection of said contact and said resistance coil to the two devices above mentioned, and a voltmeter for the'reading ofthe horsepower transmitted, and electrical circuits, connectin said resistance coils terminals to those'o said magneto generator, and connecting said voltmeter to a terminal ofasaia resistance coil and to said contact.

on dynamometer, or ap- 13o paratus for measuring power transmitted in a shaft, a direct current magneto generator, giving a voltage proportional to its speed, and driven from the shaft in which the power is to be measured, and said shaft, and means for driving said generator from said shaft, and mechanical means 'producin relative motion between two devices on sai shaft, proportional to the tor no in said shaft, and said two devices, an a fixed resistancecoil, attached to one of said two devices, and a contact bearing on said repulley, or other source of rotating power, so that a relative movement is produced between said contact and said resistance coil, depending on the change in said springs, due to the force transmitted through them to said driven shaft, and a direct current magneto generator, whose armature is set in rotation through mechanical connections to the driven shaft, and said connections, and electrical connections between said resistance coil and said magneto generator,

forming a closed circuit of fixed resistance,

and an electrical measuring instrument, electrically connected between one terminal of the above mentioned resistance coil and the sliding contact, and said electrical connections, sald measuring mstrument to lll(llcate a value bearing aconstant relation to the product of the speed of rotation ol the driven shaft, and the torque in said shaft, irrespective of how the speed of one, or the other, or both may vary.

'FR'ANCIS DEWEY EVERETT.

Witnesses JOHN It. Fmmn, THOMAS E. DALEY. 

